ANKMJ
Ankyra Medical Journal

Ankyra Medical Journal (AnkMJ), formerly known as the Journal of Translational and Practical Medicine, regularly publishes international quality issues in the field of Medicine in the light of current information.

eISSN: 3023-655X
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Case Report
Phenotypic characterization of CRB1-associated Leber congenital amaurosis in two siblings: emphasis on para-arteriolar RPE preservation
Abstract
Leber congenital amaurosis (LCA) associated with CRB1 mutations exhibits a distinct retinal phenotype, most notably para-arteriolar retinal pigment epithelium preservation (PPRPE), an important yet often under-recognized diagnostic hallmark. We report two affected female siblings from a consanguineous family who underwent comprehensive multimodal ophthalmic evaluation, including best-corrected visual acuity assessment, color fundus photography, spectral-domain optical coherence tomography (OCT), fundus autofluorescence (FAF), and full-field electroretinography (ERG). Both demonstrated congenital severe visual impairment and nystagmus. Fundus examination revealed bilateral nummular pigmentation with characteristic PPRPE, while FAF showed para-arteriolar hyperautofluorescence consistent with preserved RPE integrity. OCT demonstrated diffuse retinal thinning, macular disorganization, and peripheral atrophy, and ERG responses were markedly reduced or extinguished. Next-generation sequencing identified a homozygous pathogenic CRB1 variant, c.2843G>A, p.(Cys948Tyr) (NM_201253), classified as pathogenic according to ACMG-2015 criteria, confirming CRB1-associated LCA. Additional affected male family members further supported autosomal recessive inheritance. The coexistence of PPRPE, macular structural abnormalities, and severe electrophysiological dysfunction aligns with the established CRB1 phenotypic spectrum. These findings reinforce the diagnostic utility of PPRPE in differentiating CRB1-associated LCA from other molecular subtypes and underscore the importance of integrating multimodal imaging with early molecular testing to facilitate accurate diagnosis, targeted genetic counseling, and potential future eligibility for emerging genotype-directed therapies.

Keywords : Leber congenital amaurosis; CRB1 gene; para-arteriolar retinal pigment epithelium; optical coherence tomography; fundus autofluorescence.

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Article available in :
Volume 5, Issue 2, 2026
Page : 56-60
https://doi.org/10.51271/ANKMJ-0067
Article Information
Received : 20 Eki 2025
Accepted : 01 Ara 2025
Published : 25 Mar 2026
Corresponding Author :

Hatice Zeynep İlikli: Department of Ophthalmology, Ankara Etlik City Hospital, Ankara, Turkiye

[email protected]
Citation : İlikli HZ, Göcen TZ, Teke MY. Phenotypic characterization of CRB1-associated Leber congenital amaurosis in two siblings: emphasis on para-arteriolar RPE preservation. Ank Med J. 2026;5(2):56-60. doi:10.51271/ANKMJ-0067

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